Petroleum wells can be naturally flowing, injecting or can be produced by any means of artificial lift. The hydrocarbon production stream can include both liquid and gaseous products that are a natural byproduct of the producing wells. As hydrocarbons and water flow through the formation, gases can travel in the flow stream either separate from the liquid products or dissolved within the liquid products. The gases are carried into the production tubing and can cause problems with artificial lifting mechanisms, such as rod pumps, by reducing the volumetric efficiency of the pump.
Gas interference occurs in situations when the pump is filling with a considerable amount of free gas that is not separated before entering the pump. If the amount of free gas entering the pump can be reduced, the volumetric efficiency of the pump is improved or the total pump capacity can be increased.
To be effective, a gas separation scheme for a hydrocarbon well should provide an opportunity and space for gas dissolved or entrained in the oil to free itself from the liquid. To accomplish this, the pump intake velocity of the fluid should preferably be adjusted to a rate that is near to or less than the rate at which gas bubbles can flow through the liquid. This range is approximately 0.4 to 1.2 feet/second, with the preferable range being 0.4 to 0.7 feet/second. Also, the well should provide enough storage space for the gas free liquid in the well case so that the well ‘heads up’ and produces extremely high percentages of gas intermittently.